U.S. patent application number 15/119322 was filed with the patent office on 2017-01-12 for hard coating film and method of forming same.
This patent application is currently assigned to KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.). The applicant listed for this patent is KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.). Invention is credited to Hiroaki NII, Kenji YAMAMOTO.
Application Number | 20170009333 15/119322 |
Document ID | / |
Family ID | 53878395 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170009333 |
Kind Code |
A1 |
NII; Hiroaki ; et
al. |
January 12, 2017 |
HARD COATING FILM AND METHOD OF FORMING SAME
Abstract
The present invention relates to a hard coating film that is
formed on a substrate, that is provided with a layer (A) of which
the composition is [Ti(BCN)] and a layer (B) of which the
composition is [TiAl(CN)], [AlCr(CN)], [TiCrAlSi(CN)], or
[TiSi(CN)], and that is characterized in that: a foundation layer
comprising the layer (B) is formed on the substrate; an
adhesion-reinforcing layer in which the layer (A) and the layer (B)
are stacked repeatedly in an alternating manner is formed on the
foundation layer; the thickness of the layer (A) increases compared
to the foundation layer (2) side as the thickness of the
adhesion-reinforcing layer increases; and the maximum thickness of
the layer (A) is 20-50 nm. The hard coating film is formed on the
substrate surface of a jig tool or the like, has high coating film
hardness, and exhibits excellent adhesion and wear resistance
during cutting and the like.
Inventors: |
NII; Hiroaki; (Hyogo,
JP) ; YAMAMOTO; Kenji; (Hyogo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) |
Kobe-shi |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA KOBE SEIKO SHO
(KOBE STEEL, LTD.)
Kobe-shi
JP
|
Family ID: |
53878395 |
Appl. No.: |
15/119322 |
Filed: |
February 19, 2015 |
PCT Filed: |
February 19, 2015 |
PCT NO: |
PCT/JP2015/054694 |
371 Date: |
August 16, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 15/01 20130101;
C23C 14/0641 20130101; C23C 14/0647 20130101; C23C 14/0021
20130101; C23C 14/325 20130101; C23C 28/42 20130101; C22C 27/06
20130101; C23C 14/35 20130101; C23C 28/044 20130101; C23C 14/067
20130101; C23C 14/34 20130101; C23C 28/042 20130101; C22C 14/00
20130101; C23C 14/0664 20130101; C22C 21/00 20130101; C23C 14/024
20130101 |
International
Class: |
C23C 14/06 20060101
C23C014/06; C23C 14/32 20060101 C23C014/32; C22C 14/00 20060101
C22C014/00; C23C 14/34 20060101 C23C014/34 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 21, 2014 |
JP |
2014-032280 |
Claims
1. A hard film to be formed on a substrate, the hard film
comprising: a layer A having a composition of
Ti.sub.w(B.sub.xC.sub.1-x-yN.sub.y).sub.1-w satisfying
0.2.ltoreq.w.ltoreq.0.6 0.1.ltoreq.x.ltoreq.0.8,
0.ltoreq.y.ltoreq.0.5 and 0.ltoreq.1-x-y.ltoreq.0.5; and a layer B
having a composition of any one of
Ti.sub.1-aAl.sub.a(C.sub.1-kN.sub.k),
Al.sub.bCr.sub.1-b(C.sub.1-kN.sub.k),
Ti.sub.1-c-d-eCr.sub.cAl.sub.dSi.sub.e(C.sub.1-kN.sub.k) and
Ti.sub.1-fSi.sub.f(C.sub.1-kN.sub.k), which satisfies
0.3.ltoreq.a.ltoreq.0.7, 0.3.ltoreq.b.ltoreq.0.8,
0.3.ltoreq.d.ltoreq.0.7, c.ltoreq.0.3, 0.ltoreq.e.ltoreq.0.3,
1-c-d-e.ltoreq.0.3, 0.05.ltoreq.f.ltoreq.0.3 and
0.5.ltoreq.k.ltoreq.1, wherein an underlying layer formed of the
layer B is formed on the substrate, and an adhesion reinforcing
layer in which the layers A and the layers B are alternately
repeatedly laminated on one another is formed on the underlying
layer, and the layer A is increased in thickness compared to that
on the underlying layer side with an increase in thickness of the
adhesion reinforcing layer, and a maximum thickness of the layer A
is 20 to 50 nm.
2. The hard film according to claim 1, wherein a layer C is further
formed on the adhesion reinforcing layer, the layer C has a
composition of TiB.sub.2, and a thickness of the layer C is 5.0
.mu.m or less.
3. A method for forming the hard film according to claim 1, the
method comprising: a substrate preparation step of preparing the
substrate; a substrate heating step of heating the substrate; and a
film forming step of forming the hard film on the substrate,
wherein in the film forming step, the underlying layer and the
adhesion reinforcing layer are formed by at least one of an arc ion
plating process and a sputtering process.
4. A method for forming the hard film according to claim 2, the
method comprising: a substrate preparation step of preparing the
substrate; a substrate heating step of heating the substrate; and a
film forming step of forming the hard film on the substrate,
wherein in the film forming step, the underlying layer, the
adhesion reinforcing layer and the layer C are formed by at least
one of an arc ion plating process and a sputtering process.
Description
TECHNICAL FIELD
[0001] The present invention relates to a hard film formed on a
substrate surface of a tool such as a cutting tool or a die,
particularly a tool formed of a non-ferrous metal material, and a
method for manufacturing the same.
BACKGROUND ART
[0002] In order to improve wear resistance in cutting and the like,
a hard film formed of, for example, TiB.sub.2 or the like is
commonly formed on a surface of a substrate of a tool. Then,
technologies for forming such hard films are disclosed in Patent
Documents 1 to 4.
[0003] Patent Document 1 discloses a cutting tool insert including
a substrate and a film containing at least one TiB.sub.2 layer.
Further, Patent Document 2 discloses a cutting tool in which a hard
covering layer is formed by vapor deposition on a surface of a tool
substrate formed of a cubic boron nitride-based material sintered
under an ultrahigh pressure, and discloses that the hard film layer
is composed of a lower layer formed of a TiB.sub.2 layer, an
intermediate layer formed of a two-phase mixed layer of a TiB.sub.2
layer and a TiN layer, and an upper layer formed of a complex
nitride layer of Ti and Al.
[0004] Patent Document 3 discloses a film made by laminating a
layer A composed of a metal boride and a layer B containing carbon
on each other. Further, Patent Document 4 discloses a laminate
including a laminated part formed of at least two kinds of compound
layers mainly composed of one or more first elements selected from
the group 4a, 5a and 6a elements in the periodic table, Al, Si and
B, and one or more second elements selected from B, C, N and O, and
an intermediate layer composed of one or more third elements
selected from the group 4a, 5a and 6a elements in the periodic
table and one or more fourth elements selected from C, N and O.
PRIOR ART DOCUMENTS
Patent Documents
[0005] Patent Document 1: JP-A-2002-355704
[0006] Patent Document 2: JP-A-2010-228032
[0007] Patent Document 3: JP-A-2009-79266
[0008] Patent Document 4: JP-A-H08-127862
SUMMARY OF THE INVENTION
Problems that the Invention is to Solve
[0009] However, in the cutting tool insert of Patent Document 1,
the film formed on the substrate formed of a cemented carbide and
the like contains the TiB.sub.2 layer. The TiB.sub.2 layer is
different from the substrate in crystal structure, so that adhesion
thereof to the substrate is liable to be decreased. For this
reason, the film described in Patent Document 1 has a problem of
having inferior adhesion during cutting and the like.
[0010] In the cutting tool of Patent Document 2, the upper layer of
the hard film layer acting as a working surface in cutting and the
like has a composition of TiAlN. The film having the composition of
TiAlN is easy to wear in cutting and the like of a non-ferrous
metal material. For this reason, the hard covering layer described
in Patent Document 2 has a problem of having inferior wear
resistance during cutting and the like.
[0011] In the film of Patent Document 3, the film is formed of the
metal boride and the carbide, and the metal boride and the carbide
are low in adhesion to the substrate formed of a cemented carbide
and the like. For this reason, the film described in Patent
Document 3 has a problem of having inferior adhesion during cutting
and the like.
[0012] In the laminate of Patent Document 4, the laminated part
acting as a working surface in cutting and the like has a
composition of TiN or AlN. The film having the composition of TiN
or AlN is easy to wear in cutting and the like. For this reason,
the laminate described in Patent Document 4 has a problem of having
inferior wear resistance during cutting and the like.
[0013] The present invention has been made in view of the
above-mentioned situation, and objects thereof are to provide a
hard film formed on a substrate surface of a tool, having high film
hardness and having excellent adhesion and wear resistance during
cutting and the like, and to provide a method for forming the
same.
Means for Solving the Problems
[0014] The hard film in the present invention in order to solve the
problems is a hard film to be formed on a substrate, the hard film
including: a layer A having a composition of
Ti.sub.w(B.sub.xC.sub.1-x-yN.sub.y).sub.1-w satisfying
0.2.ltoreq.w.ltoreq.0.6, 0.1.ltoreq.x.ltoreq.0.8,
0.ltoreq.y.ltoreq.0.5 and 0.ltoreq.1-x-y.ltoreq.0.5; and a layer B
having a composition of any one of
Ti.sub.1-aAl.sub.a(C.sub.1-kN.sub.k),
Al.sub.bCr.sub.1-b(C.sub.1-kN.sub.k),
Ti.sub.1-c-d-eCr.sub.cAl.sub.dSi.sub.e(C.sub.1-kN.sub.k) and
Ti.sub.1-fSi.sub.f(C.sub.1-kN.sub.k), which satisfies
0.3.ltoreq.a.ltoreq.0.7, 0.3.ltoreq.b.ltoreq.0.8,
0.3.ltoreq.d.ltoreq.0.7, c.ltoreq.0.3, 0.ltoreq.e.ltoreq.0.3,
1-c-d-e.ltoreq.0.3, 0.05.ltoreq.f.ltoreq.0.3 and
0.5.ltoreq.k.ltoreq.1, wherein an underlying layer formed of the
layer B is formed on the substrate, and an adhesion reinforcing
layer in which the layers A and the layers B are alternately
repeatedly laminated on one another is formed on the underlying
layer, and
[0015] the layer A is increased in thickness compared to that on
the underlying layer side with an increase in thickness of the
adhesion reinforcing layer, and a maximum thickness of the layer A
is 20 to 50 nm.
[0016] The above-mentioned hard film includes the layer A and the
layer B each having the predetermined composition, thereby
increasing hardness of the hard film and improving wear resistance
of the hard film. Further, the above-mentioned hard film includes
the underlying layer formed of the layer B, thereby improving
adhesion between the film and the substrate. Furthermore, the
above-mentioned hard film includes the adhesion reinforcing layer
in which the layers A and the layers B are alternately repeatedly
laminated on one another, the layer A is increased in thickness
compared to that on the underlying layer side with an increase in
the thickness of the adhesion reinforcing layer, and the maximum
thickness thereof reaches the predetermined thickness, thereby
improving the adhesion of the hard film and improving cutting
performance to improve the wear resistance.
[0017] In the hard film in the present invention, it is preferred
that a layer C is further formed on the above-mentioned adhesion
reinforcing layer, and the above-mentioned layer C having a
composition of TiB.sub.2, and the thickness of the above-mentioned
layer C is 5.0 .mu.m or less. The above-mentioned hard film
includes the layer C composed of TiB.sub.2, and thickness of the
layer C is adjusted to the predetermined range, thereby preventing
breakage (chipping) of the hard film and improving the wear
resistance of the hard film.
[0018] The first method for forming the hard film in the present
invention includes: a substrate preparation step of preparing the
substrate; a substrate heating step of heating the substrate; and a
film forming step of forming the hard film on the substrate, and in
the film forming step, the underlying layer and the adhesion
reinforcing layer are formed by at least one of an arc ion plating
process and a sputtering process.
[0019] In the above-mentioned first method for forming the hard
film, the film forming step is performed by at least one of the arc
ion plating process and the sputtering process, thereby forming the
hard film including the underlying layer formed of the layer B
having the predetermined composition and the adhesion reinforcing
layer in which the layers A having the predetermined composition
and the layers B having the predetermined composition are
alternately repeatedly laminated on one another. This increases the
hardness of the hard film and improves the wear resistance of the
hard film. Further, in the first method for forming the hard film,
the layer A is formed in a state where a predetermined bias voltage
is applied on the substrate, thereby improving the wear resistance
of the hard film.
[0020] The second method for forming the hard film in the present
invention includes: a substrate preparation step of preparing the
substrate; a substrate heating step of heating the substrate; and a
film forming step of forming the hard film on the substrate, and in
the film forming step, the underlying layer, the adhesion
reinforcing layer and the layer C are formed by at least one of an
arc ion plating process and a sputtering process.
[0021] In the above-mentioned second method for forming the hard
film, the film forming step is performed by at least one of the arc
ion plating process and the sputtering process, thereby forming the
hard film including the underlying layer formed of the layer B
having the predetermined composition, the adhesion reinforcing
layer in which the layers A having the predetermined composition
and the layers B having the predetermined composition are
alternately repeatedly laminated on one another, and the layer C
composed of TiB.sub.2. This increases the hardness of the hard film
and improves the wear resistance of the hard film. Further, in the
second method for forming the hard film, the layer A and the layer
C are formed in a state where a predetermined bias voltage is
applied on the substrate, thereby improving the wear resistance of
the hard film.
Advantageous Effects of the Invention
[0022] In the hard film of the present invention, it is formed on a
substrate surface of a tool, and has high film hardness and
excellent adhesion and wear resistance during cutting and the like.
Further, in the forming method of the hard film of the present
invention, the hard film having high hardness and excellent
adhesion and wear resistance during cutting and the like can be
formed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a cross-sectional view showing a first embodiment
of a hard film in the present invention.
[0024] FIG. 2 is a cross-sectional view showing a second embodiment
of a hard film in the present invention.
[0025] FIG. 3 is a diagram schematically illustrating a film
deposition apparatus.
MODE FOR CARRYING OUT THE INVENTION
[0026] A first embodiment of a hard film in the present invention
will be described with reference to the drawing.
[0027] As shown in FIG. 1, a hard film 1 is a film formed on a
substrate 10 for improving adhesion and wear resistance, and
includes an underlying layer 2 and an adhesion reinforcing layer 3
formed on the underlying layer 2.
<Substrate>
[0028] Examples of the substrates 10 include cemented carbides,
iron-based alloys, cermets, high-speed tool steels and the like.
However, the substrates 10 should not be limited thereto, and may
be tools such as cutting tools such as chips, drills and end mills,
press dies, forging dies, molding dies and blanking punches.
<Underlying Layer>
[0029] The underlying layer 2 is a film formed on the substrate 10,
and is formed of a layer B having a predetermined composition. The
adhesion between the substrate 10 and the hard film 1 is improved
by the formation of the underlying layer 2. For this reason, the
thickness of the underlying layer 2 is preferably from 0.1 to 5
.mu.m. The details of the composition of the layer B will be
described later.
<Adhesion Reinforcing Layer>
[0030] The adhesion reinforcing layer 3 is a film formed on the
underlying layer 2, and is formed by alternately repeatedly
laminating layers A 4 having a predetermined composition and layers
B 5 having a predetermined composition on one another. Then, the
layer A 4 is increased in thickness compared to that on the
underlying layer 2 side with an increase in the thickness of the
adhesion reinforcing layer 3, and the adhesion reinforcing layer 3
is formed so that the maximum thickness of the layer A 4, that is,
the thickness of the uppermost layer of the layers A 4 in the
adhesion reinforcing layer 3, is 20 to 50 nm. It is more preferably
from 20 to 40 nm. The minimum thickness of the layer A 4, that is,
the thickness of the lowermost layer of the layers A 4, which is in
contact with the substrate 10, in the adhesion reinforcing layer 3,
is not particularly limited. However, it is preferably from 0.1 to
20 nm, and more preferably from 0.5 to 10 nm. The layers A 4 are
preferably increased in thickness for each lamination (for each
layer). However, they may be increased in thickness for each two or
more layers, although not shown. For example, the first and second
layers are the same in thickness, and the third layer may be
increased in thickness compared to the first and second layers.
Further, the thickness of the layers B 5 in the adhesion
reinforcing layer 3 is preferably constant for each lamination and
from 5 to 50 nm. It is more preferably from 10 to 40 nm.
[0031] In the adhesion reinforcing layer 3, it is preferred to
laminate the layers A 4 and the layers B 5 in such a manner that
the layer A 4 is disposed on the substrate 10 side thereof and that
the layer A 4 is disposed on the outermost surface side. However,
the layer B 5 may be disposed on the outermost surface side of the
adhesion reinforcing layer 3, although not shown. The thickness of
the adhesion reinforcing layer 3, that is, the total thickness of
the layers A 4 and the layers B 5 laminated on one another is
preferably from 0.5 to 10 .mu.m, and more preferably from 0.5 to 5
.mu.m.
[0032] The layer A 4 is a film having heat resistance, high
hardness and excellent wear resistance. However, when it is used as
a single layer, there is a problem in further improvement of the
wear resistance, because of a problem of the adhesion to the
substrate 10 and a problem of crystal orientation. The layer B 5 is
a film having oxidation resistance and high toughness. However,
when it is used alone, there is a problem that the wear resistance
thereof is inferior to that of the layer A 4. In the present
invention, the adhesion reinforcing layer 3 in which the layers A 4
and the layers B 5 are alternately repeatedly laminated on one
another is formed, the layers A 4 are increased in thickness
compared to that on the underlying layer 2 side with an increase in
the thickness of the adhesion reinforcing layer 3, and the maximum
thickness thereof reaches the predetermined thickness, thereby
being able to control crystal orientation of the layers A 4 and the
layers B 5. That is, in each layer B 5, coarse crystal grains
unidirectionally grow, so that adhesion thereof to an upper layer
is decreased as it is. Accordingly, by gradually increasing the
thickness of each layer A, the crystal grains in the layer B
continue to unidirectionally grow while the thickness of the layer
A is thin, and unidirectional growth of the coarse crystal grains
in the layer B is suppressed with an increase in thickness of the
layer A. As a result, an influence from a lower layer (a layer on
the underlying layer 2 side) on the unidirectional growth in the
layer B is weakened with an increase in thickness of the layer A,
and the size of the crystal grains in the layer B is refined. The
adhesion of the hard film 1 is improved thereby compared to a hard
film having a single layer structure of the layer A 4 and the layer
B 5, and cutting performance is remarkably improved, resulting in
improvement of the wear resistance of the hard film 1.
[0033] In order to control the grain size in the layers B 5, it is
preferred that the thickness of the layers A 4 in the adhesion
reinforcing layer 3 is increased stepwise. For example, the
thickness of the layers A 4 is preferably increased by 0.1 to 20 nm
for each lamination (for each layer or for each two or more
layers). When the maximum thickness of the layers A 4 in the
adhesion reinforcing layer 3 is less than 20 nm, improvement of the
cutting performance of the adhesion reinforcing layer 3 is not
recognized, and improvement of the wear resistance of the hard film
1 is not recognized. When the maximum thickness of the layers A 4
is more than 50 nm, it is difficult to form the layers A 4, also
resulting in high cost. The above-mentioned thickness of the layers
A 4 is controlled by the amount of evaporation of a layer A target
in manufacturing of the hard film 1 (in layer A formation)
described later, or the like.
(Layer A)
[0034] The layer A 4 is a film having a composition of Ti.sub.w(B,
C, N).sub.1-w satisfying 0.2.ltoreq.w.ltoreq.0.6
(0.4.ltoreq.1-w.ltoreq.0.8).
[0035] Non-metallic components (B, C and N) are elements added for
imparting high hardness and wear resistance to the layer A 4, and a
metallic component (Ti) is an element added for adjusting the
content of the non-metallic components (B, C and N). When the
atomic ratio (w) of the metallic component (Ti) is more than 0.6,
the atomic ratio (1-w) of the non-metallic components (B, C and N)
is less than 0.4 to decrease the hardness and wear resistance of
the layer A 4. Further, when the atomic ratio (w) of the metallic
component (Ti) is less than 0.2, the atomic ratio (1-w) of the
non-metallic components (B, C and N) is more than 0.8 to decrease
the hardness and wear resistance of the layer A 4.
[0036] The layer A 4 is a film in which the atomic ratio in the
nonmetallic components is (B.sub.xC.sub.1-x-yN.sub.y) and
satisfying 0.1.ltoreq.x.ltoreq.0.8, 0.ltoreq.y.ltoreq.0.5 and
0.ltoreq.1-x-y.ltoreq.0.5.
[0037] In order to impart high hardness and wear resistance to the
layer A 4, the atomic ratio (x) of B must be at least from 0.1 to
0.8. Preferably, the atomic ratio (x) of B is from 0.25 to 0.75.
Further, in order to further increase the hardness of the layer A
4, the atomic ratio (1-x-y) of C may be 0.50 or less, and the
atomic ratio (y) of N may be 0.50 or less.
(Layer B)
[0038] The layer B 5 is a film having a composition composed of
metallic components (Ti, Al, Cr and Si) and non-metallic components
(C and N) and being any one of the following four kinds.
[0039] (1) A film having a composition of
Ti.sub.1-aAl.sub.a(C.sub.1-kN.sub.k) satisfying
0.3.ltoreq.a.ltoreq.0.7 and 0.5.ltoreq.k.ltoreq.1
[0040] In order to impart high hardness and wear resistance to the
layer B 5, the atomic ratio (1-a) of Ti as the metallic component
must be from 0.3 to 0.7, and the atomic ratio (a) of Al must be
from 0.3 to 0.7. Further, in order to impart high hardness and wear
resistance to the layer B 5, at least the atomic ratio (k) of N as
the non-metallic component must be from 0.5 to 1. Furthermore, in
order to further increase the hardness of the layer B 5, the atomic
ratio (1-k) of C as the non-metallic component may be 0.5 or
less.
[0041] (2) A film having a composition of
Al.sub.bCr.sub.1-b(C.sub.1-kN.sub.k) satisfying
0.3.ltoreq.b.ltoreq.0.8 and 0.5.ltoreq.k.ltoreq.1
[0042] In order to impart high hardness and wear resistance to the
layer B 5, the atomic ratio (b) of Al as the metallic component
must be from 0.3 to 0.8, and the atomic ratio (1-b) of Cr must be
from 0.2 to 0.7. Further, in order to impart high hardness and wear
resistance to the layer B 5, at least the atomic ratio (k) of N as
the non-metallic component must be from 0.5 to 1. Furthermore, in
order to further increase the hardness of the layer B 5, the atomic
ratio (1-k) of C as the non-metallic component may be 0.5 or
less.
[0043] (3) A film having a composition of
Ti.sub.1-c-d-eCr.sub.cAl.sub.dSi.sub.e(C.sub.1-kN.sub.k) satisfying
c.ltoreq.0.3, 0.3.ltoreq.d.ltoreq.0.7, 0.ltoreq.e.ltoreq.0.3,
1-c-d-e.ltoreq.0.3 and 0.5.ltoreq.k.ltoreq.1
[0044] In order to impart high hardness and wear resistance to the
layer B 5, the atomic ratio (1-c-d-e) of Ti as the metallic
component must be 0.3 or less, the atomic ratio (c) of Cr must be
0.3 or less, and the atomic ratio (d) of Al must be from 0.3 to
0.7. Further, in order to impart high hardness and wear resistance
to the layer B 5, at least the atomic ratio (k) of N as the
non-metallic component must be from 0.5 to 1. Furthermore, in order
to further impart the wear resistance to the layer B 5, the atomic
ratio (e) of Si as the metallic component may be 0.3 or less. In
addition, in order to further increase the hardness of the layer B
5, the atomic ratio (1-k) of C as the non-metallic component may be
0.5 or less.
[0045] (4) A film having a composition of
Ti.sub.1-fSi.sub.f(C.sub.1-kN.sub.k) satisfying
0.05.ltoreq.f.ltoreq.0.3 and 0.5.ltoreq.k.ltoreq.1
[0046] In order to impart high hardness and wear resistance to the
layer B 5, the atomic ratio (1-f) of Ti as the metallic component
must be from 0.7 to 0.95, and the atomic ratio (f) of Si must be
from 0.05 to 0.3. Further, in order to impart high hardness and
wear resistance to the layer B 5, at least the atomic ratio (k) of
N as the non-metallic component must be from 0.5 to 1. Furthermore,
in order to further increase the hardness of the layer B 5, the
atomic ratio (1-k) of C as the non-metallic component may be 0.5 or
less.
[0047] In the above-mentioned underlying layer 2, layer A 4 and
layer B 5, the atomic ratios (w, x, y, a, b, c, d, e and f) of Ti,
B, C, N, Al, Cr and Si are controlled by a composition of a target
set to a film deposition apparatus 100 (see FIG. 3) in the
production of the hard film 1 (a film forming step) described
later. Further, the atomic ratios (x, y and k) of C and N may be
controlled by the introduction amount of inert gases such as
nitrogen and hydrocarbons introduced into the film deposition
apparatus 100. Then, the thickness of the underlying layer 2, the
layer A 4 and the layer B 5 is controlled by the evaporation amount
of the target during the film formation, or the like.
[0048] A second embodiment of a hard film in the present invention
will be described with reference to the drawing.
[0049] As shown in FIG. 2, a hard film 1A includes an underlying
layer 2, an adhesion reinforcing layer 3 formed of layers A 4 and
layers B 5, and a layer C 6 formed on the adhesion reinforcing
layer 3. The hard film 1A includes the layer C 6, thereby further
improving the wear resistance.
[0050] The adhesion reinforcing layer 3 formed of the underlying
layer 2, the layers A 4 and the layers B 5 is the same as in the
case of the hard film 1 of the first embodiment described above, so
that the description thereof is omitted.
(Layer C)
[0051] The layer C 6 has a composition of TiB.sub.2, and the
thickness thereof is 5.0 .mu.m or less and preferably 3.0 .mu.m or
less. When the thickness is more than 5.0 am, breakage (chipping)
of the layer C 6 occurs by internal stress to decrease the wear
resistance of the hard film 1A. Further, although the lower limit
of the thickness is not particularly limited, it is preferably 0.3
.mu.m or more in terms of easy formation of the layer C 6. The
thickness of the layer C 6 is controlled by the amount of
evaporation of a target (TiB.sub.2) set to the film deposition
apparatus 100 (see FIG. 2), during the film formation, in the
production of the hard film 1A (the film forming step).
[0052] In the layer C 6, the cutting performance of the layer C 6
varies depending on the integral intensity ratio of diffraction
lines when measured by X-ray diffraction, that is, preferential
orientation. In the layer C 6, the cutting performance of the layer
C 6 is improved by improving orientation of a (100) plane or a
(001) plane. The preferential orientation of the layer C 6 depends
on the bias voltage applied to the substrate 10 during the
formation of the layer C 6, and varies from (001) plane orientation
to (100) plane orientation with -50 V as a boundary, with an
increase in negative bias voltage.
[0053] Accordingly, when the integral intensity of a diffraction
line from a (100) plane when measured by X-ray diffraction of a
.theta.-2.theta. process is defined as I(100) and the integral
intensity of a diffraction line from a (001) plane is defined as
I(001), it is preferred that the layer C 6 satisfies
I(100)/I(001)<1, when the bias voltage is -50 V or more and less
than 0 V, and satisfies I(100)/I(001).gtoreq.1, when the bias
voltage is -150 V or more and less than -50 V using an unbalanced
magnetron sputtering (UBMS) power supply as a sputtering power
supply as described later. When the bias voltage is -100 V or more
and less than -50 V using a dual magnetron sputtering (DMS) power
supply described in a reference literature (Takuji Oyama, Past,
Present and Future of Dry Coating Technology, Res. Reports Asahi
Glass Co., Ltd., 57 (2007), pp. 83-90), it is preferred to satisfy
I(100)/I(001).gtoreq.1. Like this, by adjusting the integral
intensity ratio to the predetermined value range by the bias
voltage, the hardness of the layer C 6 is increased, and the
cutting performance is improved to improve the strength and wear
resistance of the hard film 1A.
[0054] Then, there is described a first method for forming the hard
film in the present invention, that is, a forming method of the
hard film of the first embodiment. For the structure of the hard
film 1, reference is made to FIG. 1. The forming method of the hard
film 1 includes a substrate preparation step, a substrate heating
step and a film forming step.
(Substrate Preparation Step)
[0055] The substrate preparation step is a step of preparing the
substrate 10 having a predetermined size, with cleaning with
ultrasonic waves or the like as needed.
(Substrate Heating Step)
[0056] The substrate heating step is a step of heating the
substrate 10 after introduction into the film deposition apparatus
100 as shown in FIG. 3, and the substrate 10 is preferably heated
so as to be kept at a predetermined temperature, for example, 500
to 550.degree. C. Heating of the substrate 10 makes it easy to form
the hard film 1 on the substrate 10 in the subsequent step.
(Film Forming Step)
[0057] The film forming step is a step of forming the hard film 1
on the substrate 10 by using at least one of an arc ion plating
process (AIP process) and a sputtering process (SP process).
Specifically, the underlying layer 2 is formed on the substrate 10
by the AIP process or the SP process, and the adhesion reinforcing
layer 3 is formed on the underlying layer 2 by using the SP process
or both processes of the AIP process and the SP process. Then, the
layers A 4 of the adhesion reinforcing layer 3 are formed by the SP
process, and the layers B 5 of the adhesion reinforcing layer 3 are
formed by the AIP process or the SP process. Further, when the
layers A 4 are formed by the SP process, a bias voltage of -200 V
or more and less than 0 V is preferably applied to the substrate
10.
[0058] Furthermore, in the forming method of the hard film 1 of
this embodiment, in addition to the above-mentioned steps, a
substrate etching step may be contained between the substrate
heating step and the film forming step. The substrate etching step
is a step of etching a surface of the substrate 10 with ions of a
rare gas such as Ar.
[0059] Then, the case of using the film deposition apparatus 100
shown in FIG. 3 is described as an example of the forming method of
the hard film 1. The film deposition apparatus should not be
construed as being limited thereto.
[0060] As shown in FIG. 3, the film deposition apparatus 100
includes a chamber 103 having an exhaust port for vacuum exhaust
and a gas supply port 104 for supplying a film forming gas and a
rare gas, an arc power supply 109 connected to an arc evaporation
source 101, a sputter power supply 108 connected to a sputter
evaporation source 102, a substrate stage 105 for supporting the
substrate 10 on which the film is to be formed, and a bias power
supply 107 for applying negative bias voltage to the substrate 10
through the substrate stage 105 between the substrate stage 105 and
the above-mentioned chamber 103. Further, in addition, it includes
heaters 106, a DC power supply 112 for discharge, an AC power
supply 111 for filament heating and the like.
[0061] First, a target for the underlying layer (not shown), which
is composed of various metals, alloys or metal compounds, is
attached to the arc evaporation source 101 or the sputter
evaporation source 102 of the film deposition apparatus 100, and
further, the substrate 10 is attached on the substrate stage 105.
The inside of the chamber 103 is evacuated (for example, exhausted
to 5.times.10.sup.3 Pa or less) to form a vacuum state. Thereafter,
Ar is introduced as the rare gas into the chamber 103, and the
substrate 10 is heated to a predetermined temperature with the
heaters 106 in the chamber 103 to perform etching with Ar ions by
an ion source due to thermal electron emission from a filament
110.
[0062] Then, the target for the underlying layer is evaporated by
the arc power supply 109 or the sputter power supply 108, while
introducing the film forming gas (N.sub.2, hydrocarbons and the
like) into the chamber 103 as needed, and the substrate stage 105
supporting the substrate 10 is rotated to form the underlying layer
2 having a predetermined thickness on the substrate 10. The
thickness of the underlying layer 2 is controlled by the electric
power inputted into the arc evaporation source 101 or the sputter
evaporation source 102 (the amount of evaporation of the target for
the underlying layer) and the rotation speed and rotation number of
the substrate stage 105. The higher rotation speed of the substrate
stage 105 causes the thinner thickness of the underlying layer
2.
[0063] Next, a target for the layer A (not shown), which is
composed of various metals, alloys or metal compounds, is attached
to the sputter evaporation source 102, and a target for the layer B
(not shown), which is composed of various metals, alloys or metal
compounds, is attached to the sputter evaporation source 102 or the
arc evaporation source 101. Further, the target for the layer A and
the target for the layer B are concurrently evaporated by the
sputter power supply 108 or the sputter power supply 108 and the
arc power supply 109, while introducing the film forming gas into
the chamber 103 as needed. At this time, the substrate stage 105
supporting the substrate 10 (a body to be treated) on which the
underlying layer 2 is formed is rotated, whereby the adhesion
reinforcing layer 3 in which the layers A 4 and the layers B 5 are
alternately laminated on one another is formed on the underlying
layer. Then, the layers A 4 in the adhesion reinforcing layer 3 are
formed so as to increase in thickness for each lamination.
[0064] The body to be treated alternately passes in front of the
evaporation sources to which the targets having different
composition are each attached, with the rotation of the substrate
stage 105. At that time, the films corresponding to the target
composition of the respective evaporation sources are alternately
formed, thereby making it possible to form the adhesion reinforcing
layer 3 in which the layers A 4 and the layers B 5 are alternately
laminated on one another. Further, the thickness of each of the
layers A 4 and the layers B 5 and the amount of increase in
thickness of the layers A 4 are controlled by the electric power
inputted into each evaporation source (the amount of evaporation of
each target) and the rotation speed and rotation number of the
substrate stage 105. The higher rotation speed of the substrate
stage 105 causes the thinner thickness per layer. The evaporation
of the target for the layer A and the target for the layer B is not
limited to be concurrently performed, and the evaporation of the
target for the layer B may be performed after the formation of the
layer A.
[0065] During the layer A formation, a bias voltage of -200 V or
more and less than 0 V, preferably -150 V or more and -10 V or less
is preferably applied to the substrate 10 (the substrate 10 on
which the underlying layer 2 is formed) from the bias power supply
107 through the substrate stage 105. Application of a bias voltage
within the predetermined range to the substrate 10 improves the
cutting performance of the hard film to improve the wear
resistance. When the negative voltage of the bias voltage is
increased, heating of the substrate 10 during the film formation or
a decrease in film formation rate occurs. Accordingly, the layer A
is not uniformly formed, and breakage (chipping) becomes liable to
occur in the hard film 1 during cutting, resulting in easy
deterioration of the wear resistance.
[0066] Further, as the sputter power supply 108 used during the
layer A formation, there can be used a UBMS power supply (normal
power supply) such as UBMS 202 manufactured by Kobe Steel, Ltd., a
DMS power supply or the like. The DMS power supply is preferred as
the sputter power supply 108. Use of the DMS power supply as the
sputter power supply 108 can more improve the hardness and the wear
resistance than the case of the normal power supply (UBMS power
supply). The reason why the hardness is increased by using the DMS
is considered to be that ion irradiation of the target for the
layer A is increased by the DMS power supply.
[0067] There is described a second forming method of the hard film
in the present invention, that is, a forming method of the hard
film of the second embodiment. For the structure of the hard film
1A, reference is made to FIG. 2.
[0068] The forming method of the hard film 1A includes a substrate
preparation step, a substrate heating step and a film forming step.
The substrate preparation step and the substrate heating step are
the same as described in the above-mentioned first forming method
(the forming method of the hard film 1 described in FIG. 1), so
that the descriptions thereof are omitted. Further, the forming
method of the hard film 1A may contain the above-mentioned
substrate etching step between the substrate heating step and the
film forming step.
(Film Forming Step)
[0069] The film forming step is a step of forming the underlying
layer 2 and the adhesion reinforcing layer 3 of the layers A 4 and
the layers B 5 on/above the substrate 10 in the same manner as in
the first forming method described above, and thereafter forming
the layer C 6 on the adhesion reinforcing layer 3 by the SP process
or the AIP process. Then, when the layer C 6 is formed by the SP
process, the UBMS power supply, the DMS power supply or the like is
used as the sputter power supply, and the DMS power supply is
preferably used. Then, during the layer C formation, the bias
voltage is preferably applied to the substrate 10. When the layer C
6 is formed by the SP process, a bias voltage of -100 V or more and
less than 0 V is preferably applied to the substrate 10 in the case
of using the DMS power supply, and a bias voltage of -150 V or more
and less than 0 V is preferably applied to the substrate 10 in the
case of using the UBMS power supply.
[0070] In the forming method of the layer C 6 in the film
deposition apparatus 100 in FIG. 3, a target for the layer C
composed of TiB.sub.2 is attached to the sputter evaporation source
102, the target for the layer C is evaporated by the sputter power
supply 108, and the substrate stage 105 supporting the substrate 10
(a body to be treated) on which the underlying layer 2 and the
adhesion reinforcing layer 3 are formed is rotated, thereby forming
the layer C 6 having a predetermined thickness on the adhesion
reinforcing layer 3 of the body to be treated. The thickness of the
layer C 6 is controlled by the electric power inputted into the
sputter power supply 108 (the amount of evaporation of the target
for the layer C) and the rotation speed and rotation number of the
substrate stage 105. The higher rotation speed of the substrate
stage 105 causes the thinner thickness of the layer C 6.
[0071] During the layer C formation, in the case of the DMS power
supply, a bias voltage of -100 V or more and less than 0 V,
preferably -100 V or more and less than -10 V, more preferably -90
V or more and less than -20 V is preferably applied, and in the
case of the UBMS power supply, a bias voltage of -150 V or more and
less than 0 V, preferably -120 V or more and less than -20 V is
preferably applied, to the substrate 10 (the substrate 10 on/above
which the underlying layer 2 and the adhesion reinforcing layer 3
are formed) from the bias power supply 107 through the substrate
stage 105.
[0072] Application of a bias voltage within the predetermined range
to the substrate 10 improves the hardness and the wear resistance
of the hard film 1A. When the negative voltage of the bias voltage
is increased, the hardness of the layer C 6 is increased. However,
heating of the substrate 10 during the film formation or a decrease
in film formation rate occurs. Accordingly, the layer C 6 is not
uniformly formed, and breakage (chipping) becomes liable to occur
in the hard film 1A during cutting, resulting in deterioration of
the wear resistance. Further, the reason why hardness is increased
by applying the bias voltage is considered to be that the potential
difference between the target for the layer C and the substrate 10
is increased to increase ion irradiation of the target for the
layer C. Furthermore, when the bias voltage applied to the
substrate 10 during the layer C formation is controlled within the
predetermined range, preferential orientation of the layer C 6,
that is, the integral intensity ratio of diffraction lines measured
by X-ray diffraction, is preferably within the predetermined range.
Specifically, when the bias voltage is from -50 V or more and less
than 0 V, the integral intensity of a diffraction line of a (100)
plane is preferably less than 1 time the integral intensity of a
diffraction line of a (001) plane, and when the bias voltage is
from -150 V or more and less than -50 V using the UBMS power
supply, the integral intensity of a diffraction line of a (100)
plane is preferably 1.0 time or more the integral intensity of a
diffraction line of a (001) plane. When the bias voltage is from
-100 V or more and less than -50 V using the DMS power supply, the
integral intensity of a diffraction line of a (100) plane is
preferably 1.0 time or more the integral intensity of a diffraction
line of a (001) plane.
EXAMPLES
[0073] Examples according to the present invention will be
described below. In the examples, hard films were formed by using
the film deposition apparatus shown in FIG. 3. The present
invention should not be construed as being limited to the following
examples.
First Example
[0074] In a first example, film formation was performed using
various compositions for both of layers A and layers B. After an
underlying layer formed of the layer B was formed to have a
thickness of 1.5 .mu.m, an adhesion reinforcing layer was formed to
have a thickness of 1.5 .mu.m. A UBMS power supply or a DMS power
supply was used for the formation of the layers A in the adhesion
reinforcing layer. The film was formed by fixing the bias voltage
during the formation of the layer A to -40 V. The layers A and
layers B each having different composition were formed, and the
thicknesses (the thickness of a lowermost layer, the amount of
increase in thickness and the thickness of the uppermost layer (the
maximum thickness)) of the layers A in the adhesion reinforcing
layer were changed, thereby examining the influence thereof on the
hardness, the adhesion and the wear resistance. Further, in
comparative examples, the layer A or the layer B was also formed as
a single layer having a thickness of 3.0 am.
[0075] Specifically, a cutting tool (chip) and a mirrored cemented
carbide test piece (13 mm square.times.5 mm thick) as substrates
were subjected to ultrasonic cleaning in ethanol, and each
substrate was attached to the substrate stage. Further, an
underlying layer target (target diameter: 100 mm.phi.) was attached
to the arc evaporation source. After the inside of the film
deposition apparatus was exhausted to 5.times.10.sup.3 Pa, the
substrate was heated to 500.degree. C., and then, etching with Ar
ions was performed for 5 minutes. Thereafter, the substrate stage
was rotated at a rotation speed of 5 rpm, and a nitrogen gas or a
mixed gas obtained by adding a carbon-containing gas to a nitrogen
gas as needed was introduced therein up to 4 Pa. Then, the arc
evaporation source was operated at a discharge current of 150 A to
form the underlying layer having a thickness of 1.5 .mu.m.
[0076] Next, a layer A target (target diameter: 152.4 mm.phi.) was
attached to the sputter evaporation source, a layer B target (the
same as the underlying layer target) was attached to the arc
evaporation source, and the substrate stage was rotated at a
rotation speed of 5 rpm. First of all, only the layer A target was
singly evaporated in the predetermined atmosphere of the
above-mentioned nitrogen gas or the like for a short period of
time, and a bias voltage of -40 V was applied to the substrate to
form the layer A (lowermost layer) having a predetermined
thickness. Thereafter, an argon gas was introduced, and the layer B
target was evaporated, thereby concurrently evaporating the layer A
target and the layer B target. The substrate stage was rotated at a
rotation speed of 5 rpm while applying a bias voltage of -40 V to
the substrate, whereby the adhesion reinforcing layer in which the
layers A and the layers B were alternately laminated on one another
was formed on the underlying layer so as to give a total thickness
of 1.5 .mu.m. Further, the thickness of the lowermost layer, the
amount of increase in thickness and the uppermost layer of the
layers A and the thickness of the layers B were as shown in Tables
1 to 5.
[0077] After the film formation, the component composition in the
hard film was measured, and the hardness, the adhesion and the wear
resistance were evaluated. The results thereof are shown in Tables
1 to 5.
(Component Composition)
[0078] The component composition of the underlying layer and the
adhesion reinforcing layer formed of the layers A and the layers B
was measured with an EPMA (electron probe micro analyzer).
(Hardness)
[0079] The hardness was measured by a nanoindenter test using the
cemented carbide test piece on which the hard film was formed. In
the measurement with a nanoindenter, "ENT-1100 manufactured by
Elionix Inc." was used as a device, and a Bercovici triangular
pyramid indenter was used as the indenter. First, five load
application curves were measured for respective loads of 2, 5, 7,
10 and 20 mN. Then, correction of data was performed by the method
of correcting the compliance of device and the indenter tip shape,
which was proposed by SAWA et al. (J. Mater. Res., Vol. 16, No. 11,
3084 (2001)). One having a hardness of 25 GPa or more was evaluated
as good, and one having a hardness of less than 25 GPa was
evaluated as poor.
(Adhesion)
[0080] The adhesion was evaluated by a scratch test using the
cemented carbide test piece on which the hard film was formed. The
scratch test was performed by moving a diamond indenter of 200
.mu.mR on the hard film under conditions of a load increase speed
of 100 N/min and an indenter moving speed of 10 mm/min. As the
critical load value, a scratched part was observed under an optical
microscope after the scratch test, and the load at a part where
damage has occurred on the film was employed as the critical load.
In Tables 1 to 5, this is described as adhesion force (N). One
having an adhesion force of 35 N or more was evaluated as good in
adhesion, and one having an adhesion force of less than 35 N was
evaluated as poor in adhesion.
(Wear Resistance)
[0081] The wear resistance was evaluated by performing a cutting
test under the following conditions, using the cutting tool (chip)
on which the hard film was formed, and measuring the boundary wear
amount (flank wear width) after passage by a predetermined
distance. One having a flank wear width of 50 .mu.m or less was
evaluated as good in wear resistance, and one having a flank wear
width of more than 50 .mu.m was evaluated as poor in wear
resistance. One that was unmeasurable due to the occurrence of
chipping was evaluated as poor in wear resistance, considering the
flank wear amount as being more than 50 km.
[Cutting Test Conditions]
[0082] Material to be cut: Ti.sub.6Al.sub.4V
[0083] Chip: TH10 (a cemented carbide chip manufactured by Tungaloy
Corporation)
[0084] Tool: Front mill (manufactured by Sumitomo Electric
Industries, Ltd.: FPG 4160R), only one chip was attached to the
front mill.
[0085] Cutting depth: 1 mm
[0086] Feed speed: 157 mm/min
[0087] Rotation speed: 1570 rpm
[0088] Peripheral speed: 100 m/min
[0089] Cutting oil: Almaredge 10%
[0090] Evaluation condition: Flank wear width (boundary part) after
7 mm cutting
TABLE-US-00001 TABLE 1 Underlying Layer Adhesion Reinforcing Layer
(thickness: 1.5 .mu.m) (thickness: 1.5 .mu.m) Layer A Composition
Composition Thickness (nm) (atomic ratio) (atomic ratio) Amount
Maximum Ti Al C N Power Ti B C N Power Lowermost of Thickness No. 1
- a a 1 - k k Supply w x 1 - x - y y Supply Layer Increase
(Uppermost Layer) 1 Comparative 0.20 0.80 0.00 1.00 AIP 0.50 0.50
0.00 0.50 UBMS 2 0.1 31 Example 2 Example 0.35 0.65 0.00 1.00 AIP
0.50 0.50 0.00 0.50 UBMS 2 0.1 34 3 Comparative 0.50 0.50 0.00 1.00
AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 17 Example 4 Example 0.50 0.50
0.00 1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 21 5 Example 0.50 0.50
0.00 1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 36 6 Example 0.50 0.50
0.00 1.00 AIP 0.50 0.50 0.00 0.50 DMS 2 0.1 38 7 Example 0.50 0.50
0.40 0.60 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 29 8 Example 0.70 0.30
0.00 1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 35 9 Example 0.70 0.30
0.00 1.00 AIP 0.50 0.50 0.00 0.50 DMS 2 0.1 36 10 Example 0.50 0.50
0.00 1.00 AIP 0.33 0.50 0.25 0.25 UBMS 2 0.1 28 11 Example 0.50
0.50 0.00 1.00 AIP 0.33 0.50 0.25 0.25 DMS 2 0.1 30 12 Comparative
0.80 0.20 0.00 1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 31 Example
13 Comparative 0.35 0.65 0.60 0.40 AIP 0.50 0.50 0.00 0.50 UBMS 2
0.1 33 Example 14 Comparative 0.50 0.50 0.00 1.00 AIP 0.50 0.00
0.50 0.50 UBMS 2 0.1 35 Example 15 Comparative 0.50 0.50 0.00 1.00
AIP 0.50 0.00 0.50 0.50 UBMS 2 0.1 32 Example Adhesion Reinforcing
Layer (thickness: 1.5 .mu.m) Layer B Wear Resistance Composition
Thickness Hardness Adhesion Flank wear Width No. Power Supply (nm)
(GPa) (N) (.mu.m) 1 Comparative The same as in the underlying layer
20 18 42 Unmeasurable Example 2 Example The same as in the
underlying layer 20 31 83 39 3 Comparative The same as in the
underlying layer 20 26 21 67 Example 4 Example The same as in the
underlying layer 20 26 42 47 5 Example The same as in the
underlying layer 20 27 76 37 6 Example The same as in the
underlying layer 20 35 78 32 7 Example The same as in the
underlying layer 20 32 76 22 8 Example The same as in the
underlying layer 20 29 77 35 9 Example The same as in the
underlying layer 20 32 78 27 10 Example The same as in the
underlying layer 20 28 45 44 11 Example The same as in the
underlying layer 20 31 56 33 12 Comparative The same as in the
underlying layer 20 16 31 58 Example 13 Comparative The same as in
the underlying layer 20 12 14 Unmeasurable Example 14 Comparative
The same as in the underlying layer 20 24 23 64 Example 15
Comparative The same as in the underlying layer 20 27 34 94 Example
(Note) Unmeasurable: Unmeasurable due to the occurrence of
chipping.
TABLE-US-00002 TABLE 2 Adhesion Reinforcing Layer (thickness: 1.5
.mu.m) Underlying Layer Layer A (thickness: 1.5 .mu.m) Thickness
(nm) Composition Composition Maximum (atomic ratio) (atomic ratio)
Amount Thickness Al Cr C N Power Ti B C N Power Lowermost of
(Uppermost No. b 1 - b 1 - k k Supply w x 1 - x - y y Supply Layer
Increase Layer) 16 Comparative 0.10 0.90 0.00 1.00 AIP 0.50 0.50
0.10 0.40 UBMS 2 0.1 36 Example 17 Example 0.30 0.70 0.00 1.00 AIP
0.50 0.50 0.10 0.40 UBMS 2 0.1 32 18 Example 0.50 0.50 0.00 1.00
AIP 0.50 0.50 0.10 0.40 UBMS 2 0.1 33 19 Example 0.50 0.50 0.00
1.00 AIP 0.50 0.50 0.10 0.40 DMS 2 0.1 34 20 Example 0.50 0.50 0.40
0.60 AIP 0.50 0.50 0.10 0.40 UBMS 2 0.1 33 21 Example 0.75 0.25
0.00 1.00 AIP 0.50 0.50 0.10 0.40 UBMS 2 0.1 31 22 Comparative 0.85
0.15 0.00 1.00 AIP 0.50 0.50 0.10 0.40 UBMS 2 0.1 35 Example 23
Comparative 0.50 0.50 0.80 0.20 AIP 0.50 0.50 0.10 0.40 UBMS 2 0.1
34 Example 24 Comparative 0.50 0.50 0.00 1.00 AIP 0.50 0.50 0.10
0.40 UBMS 2 0.1 18 Example Adhesion Reinforcing Layer (thickness:
1.5 .mu.m) Layer B Wear Resistance Composition Thickness Hardness
Adhesion Flank wear Width No. Power Supply (nm) (GPa) (N) (.mu.m)
16 Comparative The same as in the underlying layer 20 26 31 89
Example 17 Example The same as in the underlying layer 20 34 75 40
18 Example The same as in the underlying layer 20 32 81 32 19
Example The same as in the underlying layer 20 36 82 26 20 Example
The same as in the underlying layer 20 35 76 25 21 Example The same
as in the underlying layer 20 33 72 26 22 Comparative The same as
in the underlying layer 20 27 41 Unmeasurable Example 23
Comparative The same as in the underlying layer 20 25 35
Unmeasurable Example 24 Comparative The same as in the underlying
layer 20 24 13 69 Example (Note) Unmeasurable: Unmeasurable due to
the occurrence of chipping.
TABLE-US-00003 TABLE 3 Adhesion Reinforcing Layer (thickness: 1.5
.mu.m) Underlying Layer (thickness: 1.5 .mu.m) Layer A Composition
Thickness (nm) (atomic ratio) Composition Maximum Ti (atomic ratio)
Lower- Amount Thickness 1 - c - Cr Al Si C N Power Ti B C N Power
most of (Uppermost No. d - e c d e 1 - k k Supply w x 1 - x - y y
Supply Layer Increase Layer) 25 Comparative 0.30 0.40 0.30 0.00
0.00 1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 37 Example 26 Example
0.30 0.30 0.40 0.00 0.00 1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 36
27 Example 0.20 0.30 0.50 0.00 0.00 1.00 AIP 0.50 0.50 0.00 0.50
UBMS 2 0.1 32 28 Example 0.10 0.20 0.60 0.10 0.00 1.00 AIP 0.50
0.50 0.00 0.50 UBMS 2 0.1 34 29 Example 0.10 0.20 0.60 0.10 0.20
0.80 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 31 30 Example 0.10 0.20
0.60 0.10 0.20 0.80 AIP 0.50 0.50 0.00 0.50 DMS 2 0.1 30 31 Example
0.00 0.10 0.70 0.30 0.00 1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 34
32 Comparative 0.20 0.20 0.20 0.40 0.00 1.00 AIP 0.50 0.50 0.00
0.50 UBMS 2 0.1 37 Example 33 Comparative 0.00 0.00 0.80 0.20 0.00
1.00 AIP 0.50 0.50 0.00 0.50 UBMS 2 0.1 33 Example Adhesion
Reinforcing Layer (thickness: 1.5 .mu.m) Layer B Wear Resistance
Composition Thickness Hardness Adhesion Flank wear Width No. Power
Supply (nm) (GPa) (N) (.mu.m) 25 Comparative The same as in the
underlying layer 20 26 54 86 Example 26 Example The same as in the
underlying layer 20 35 75 44 27 Example The same as in the
underlying layer 20 33 74 37 28 Example The same as in the
underlying layer 20 37 75 24 29 Example The same as in the
underlying layer 20 38 80 13 30 Example The same as in the
underlying layer 20 39 85 10 31 Example The same as in the
underlying layer 20 25 85 43 32 Comparative The same as in the
underlying layer 20 16 36 113 Example 33 Comparative The same as in
the underlying layer 20 24 5 Unmeasurable Example (Note)
Unmeasurable: Unmeasurable due to the occurrence of chipping.
TABLE-US-00004 TABLE 4 Adhesion Reinforcing Layer (thickness: 1.5
.mu.m) Underlying Layer Layer A (thickness: 1.5 .mu.m) Thickness
(nm) Composition Composition Maximum (atomic ratio) (atomic ratio)
Amount Thickness Ti Si C N Power Ti B C N Power Lowermost of
(Uppermost No. 1 - f f 1 - k k Supply w x 1 - x - y y Supply Layer
Increase Layer) 34 Comparative 1.00 0.00 0.00 1.00 AIP 0.33 0.50
0.25 0.25 UBMS 2 0.1 38 Example 35 Example 0.95 0.05 0.00 1.00 AIP
0.33 0.50 0.25 0.25 UBMS 2 0.1 32 36 Example 0.85 0.15 0.00 1.00
AIP 0.33 0.50 0.25 0.25 UBMS 2 0.1 33 37 Example 0.85 0.15 0.00
1.00 AIP 0.33 0.50 0.25 0.25 DMS 2 0.1 33 38 Example 0.75 0.25 0.00
1.00 AIP 0.33 0.50 0.25 0.25 UBMS 2 0.1 35 39 Comparative 0.65 0.35
0.00 1.00 AIP 0.33 0.50 0.25 0.25 UBMS 2 0.1 31 Example Adhesion
Reinforcing Layer (thickness: 1.5 .mu.m) Layer B Wear Resistance
Composition Thickness Hardness Adhesion Flank wear Width No. Power
Supply (nm) (GPa) (N) (.mu.m) 34 Comparative The same as in the
underlying layer 20 12 2 Unmeasurable Example 35 Example The same
as in the underlying layer 20 29 76 35 36 Example The same as in
the underlying layer 20 31 78 32 37 Example The same as in the
underlying layer 20 36 84 19 38 Example The same as in the
underlying layer 20 30 80 39 39 Comparative The same as in the
underlying layer 20 23 53 93 Example (Note) Unmeasurable:
Unmeasurable due to the occurrence of chipping.
TABLE-US-00005 TABLE 5 Layer B (thickness: 3.0 .mu.m) Layer A
(thickness: 3.0 .mu.m) Wear Resistance Power Composition (atomic
Power Hardness Adhesion Flank wear Width No. Composition (atomic
ratio) Supply ratio) Supply (GPa) (N) (.mu.m) 40 Comparative
Ti.sub.0.50Al.sub.0.50N AIP -- DMS 24 91 106 Example 41 Comparative
Al.sub.0.50Cr.sub.0.50N AIP -- DMS 25 92 123 Example 42 Comparative
Ti.sub.0.10Cr.sub.0.20Al.sub.0.60Si.sub.0.10N AIP -- DMS 29 94 79
Example 43 Comparative Ti.sub.0.85Si.sub.0.15N AIP -- DMS 31 100 86
Example 44 Comparative -- AIP
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 DMS 14 3 Unmeasurable
Example (Note) Unmeasurable: Unmeasurable due to the occurrence of
chipping.
[0091] As sown in Table 1, in Nos. 2 and 4 to 11 (examples), the
hard films satisfied the requirements of the present invention, so
that the hardness, the adhesion and the wear resistance were good.
On the other hand, in No. 1 (comparative example), Ti in the
underlying layer and the layers B was less than the lower limit,
and Al was more than the upper limit, so that the hardness and the
wear resistance were poor. In No. 3 (comparative example), the
thickness of the uppermost layer (the maximum thickness) of the
layers A was less than the lower limit, so that the adhesion and
the wear resistance were poor. In No. 12 (comparative example), Ti
in the underlying layer and the layers B was more than the upper
limit, and Al was less than the lower limit, so that the hardness,
the adhesion and the wear resistance were poor. In No. 13
(comparative example), C in the underlying layer and the layers B
was more than the upper limit, so that the hardness, adhesion and
the wear resistance were poor. In No. 14 (comparative example), the
layers A did not contain B, so that the hardness, adhesion and the
wear resistance were poor. In No. 15 (comparative example), the
layers A did not contain B, so that the adhesion and the wear
resistance were poor.
[0092] As shown in Table 2, in Nos. 17 to 21 (examples), the hard
films satisfied the requirements of the present invention, so that
the hardness, the adhesion and the wear resistance were good. On
the other hand, in No. 16 (comparative example), Al in the
underlying layer and the layers B was less than the lower limit,
and Cr was more than the upper limit, so that the adhesion and the
wear resistance were poor. In No. 22 (comparative example), Al in
the underlying layer and the layers B was more than the upper
limit, so that the wear resistance was poor. In No. 23 (comparative
example), C in the underlying layer and the layers B was more than
the upper limit, so that the wear resistance was poor. In No. 24
(comparative example), the thickness of the uppermost layer (the
maximum thickness) of the layers A was less than the lower limit,
so that the hardness, the adhesion and the wear resistance were
poor.
[0093] As shown in Table 3, in Nos. 26 to 31 (examples), the hard
films satisfied the requirements of the present invention, so that
the hardness, the adhesion and the wear resistance were good. On
the other hand, in No. 25 (comparative example), Cr in the
underlying layer and the layers B was more than the upper limit, so
that the wear resistance was poor. In No. 32 (comparative example),
Si in the underlying layer and the layers B was more than the upper
limit, so that the hardness and the wear resistance were poor. In
No. 33 (comparative example), Al in the underlying layer and the
layers B was more than the upper limit, so that the hardness, the
adhesion and the wear resistance were poor.
[0094] As shown in Table 4, in Nos. 35 to 38 (examples), the hard
films satisfied the requirements of the present invention, so that
the hardness, the adhesion and the wear resistance were good. On
the other hand, in No. 34 (comparative example), the underlying
layer and the layers B did not contain Si, so that the hardness,
the adhesion and the wear resistance were poor. In No. 39
(comparative example), Ti in the underlying layer and the layers B
was less than the lower limit, and Si was more than the upper
limit, so that the hardness and the wear resistance was poor.
[0095] As shown in Table 5, in No. 40 (comparative example), the
hard film was formed of the layers B alone, so that the hardness
and the wear resistance were poor. In Nos. 41 to 43 (comparative
examples), the hard films were formed of the layers B alone, so
that the wear resistance was poor. In No. 44 (comparative example),
the hard film was formed of the layers A alone, so that the
hardness, the adhesion and the wear resistance were poor.
Second Example
[0096] In a second example, experiments of forming a layer C on an
adhesion reinforcing layer and changing the thickness of the layer
C were carried out. The film composition and the thickness of an
underlying layer and the adhesion reinforcing layer were fixed.
After the formation of the underlying layer having a thickness of
1.5 .mu.m, layers A and layers B each having a thickness of 20 nm
were alternately laminated on one another in the adhesion
reinforcing layer, and the layers A were increased in thickness
from 2 nm (the lowermost layer) to a maximum thickness of 30 nm
(the uppermost layer), thereby forming the film so as to have a
thickness of 1.5 .mu.m as the adhesion reinforcing layer.
Thereafter, the layer C was formed to have a thickness shown in
Table 6. Then, the influence of the thickness of the layer C on the
hardness, the adhesion and the wear resistance was examined.
[0097] Specifically, in the same manner as in the above-mentioned
first example, the underlying layer and the adhesion reinforcing
layer were formed on a substrate. Then, a TiB.sub.2 target (target
diameter: 152.4 mm.phi.) as a layer C target was attached to the
sputter evaporation source. The substrate stage was rotated at a
rotation speed of 5 rpm, and a bias voltage of -40 V was applied to
the substrate to evaporate the TiB.sub.2 target, thereby forming
the layer C having a predetermined thickness. For the formation of
the layer A and the formation of the layer C, the UBMS power supply
or the DMS power supply was used. Further, no adhesion reinforcing
layer was formed on the underlying layer, and a bias voltage of -25
V was applied to the substrate to form only the layer C.
[0098] After the completion of the film formation, the component
composition in the hard film was measured, and the hardness, the
adhesion and the wear resistance were evaluated. The results
thereof are shown in Table 6.
[0099] The measuring method of the component composition and the
evaluation methods of the hardness, the adhesion and the wear
resistance are the same as in the above-mentioned first example.
For the component compositions in the hard film, the underlying
layer was "Ti.sub.0.50Al.sub.0.50N", the layer A was
"Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50", and the layer B was
"Ti.sub.0.50Al.sub.0.50N".
TABLE-US-00006 TABLE 6 Underlying Wear Layer, Resistance Layer A
Layer B Layer C Flank wear Composition Power Composition Thickness
Power Hardness Adhesion Width No. (atomic ratio) Supply (atomic
ratio) Composition (.mu.m) Supply (GPa) (N) (.mu.m) 45 Example
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 UBMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 0.5 UBMS 30 81 37 46 Example
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 UBMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 1 UBMS 33 82 23 47 Example
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 UBMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 2 UBMS 34 84 12 48 Example
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 UBMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 3 UBMS 38 82 10 49 Example
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 UBMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 4 UBMS 47 75 24 50 Example
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 UBMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 5 UBMS 45 73 47 51 Example
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 DMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 0.6 DMS 38 95 13 52 Comparative
Ti.sub.0.50(B.sub.0.50N.sub.0.50).sub.0.50 UBMS
Ti.sub.0.50Al.sub.0.50N TiB.sub.2 6 UBMS 49 68 Unmeasurable Example
53 Comparative -- -- Ti.sub.0.50Al.sub.0.50N TiB.sub.2 1 UBMS 27 21
92 Example (Note) Unmeasurable: Unmeasurable due to the occurrence
of chipping. (Note) No. 53 had no adhesion reinforcing layer
(layers A and layers B).
[0100] As shown in Table 6, in Nos. 45 to 51 (examples), the hard
films satisfied the requirements of the present invention, so that
the hardness, the adhesion and the wear resistance were good. In
No. 52 (comparative example), the thickness of the layer C was more
than the upper limit, so that the wear resistance was poor. In No.
53 (comparative example), the hard film was formed of the
underlying layer and the layer C, and no adhesion reinforcing layer
was formed, so that the adhesion and the wear resistance was
poor.
[0101] While the present invention has been described in detail
with reference to specific embodiments, it will be apparent to
those skilled in the art that various changes and modifications can
be made without departing from the spirit and scope of the present
invention.
[0102] This application is based on Japanese Patent Application No.
2014-032280 filed on Feb. 21, 2014, the entire contents of which
are incorporated herein by reference.
DESCRIPTION OF REFERENCE NUMERALS AND SIGNS
[0103] 1, 1A: Hard film [0104] 2: Underlying layer [0105] 3:
Adhesion reinforcing layer [0106] 4: Layer A [0107] 5: Layer B
[0108] 6: Layer C [0109] 10: Substrate [0110] 100: Film deposition
apparatus [0111] 101: Arc evaporation source [0112] 102: Sputter
evaporation source [0113] 103: Chamber [0114] 104: Gas supply port
[0115] 105: Substrate stage [0116] 106: Heater [0117] 107: Bias
power supply [0118] 108: Sputter power supply [0119] 109: Arc power
supply [0120] 110: Filament [0121] 111: AC power supply for
filament heating [0122] 112: DC power supply for discharge
* * * * *